Turnbuckles are known in the art, and have been used for tightening a rod, strand or rope. Typical turnbuckles are made of metal, such as steel or brass, and typically have two threaded ends which receive the threaded ends of rods or the like. The threaded ends are threaded in opposite hand, so that by turning the turnbuckle the rods, strands or ropes on both ends may be loosened or tightened.
Turnbuckles have been used in sailing ships for pre-loading the mast or masts in tension. A ship's standing rigging, such as the side stays that hold up the mast or masts, may be placed in tension to thereby place the mast or masts in tension by tightening turnbuckles attached to the stays. Loads of 100-30,000 pounds or more are typically placed on the turnbuckle.
The turnbuckles used on the side stays in sailing vessels may be located several feet above the water line, particularly if the mast has one or more spreaders. These metal turnbuckles therefore contribute not only to the overall weight of the ship, but also affect the center of gravity and overall stability of the ship. In so doing, the metal turnbuckles contribute to problems with moments and produce a multiplier effect due to the distance above the water line, requiring a higher weight keel to overcome the effects of the moments and multiplier.
In addition, the metal turnbuckles have been subject to oxidation, reducing their useful lives and detracting from the appearance of the products. This oxidation problem is worsened in the harsh environments encountered in sailing, particularly in the ocean sailing environment.
Such prior art turnbuckles have typically been made by casting the entire metal turnbuckle as one piece.